Process for the recovery of volatile solvents



i Patented lVlaLZO, 1928. I I

' uuir'l mm nanny new, or rams, FRANCE.

PBOCESSIOB THE RECOVERY OF VOLATILE SOLVENTS.

No Drawing. Application filed August 1, 1925, Serial No. 47,648; and inFrance June 8, 1925.

My invention relates to a process for the used herein constitute thehydrogen addition recovery, on the continuous working prinproducts ofterpenes. They can be made,

ciple, of volatile solvents which are brought for example, by theprocess as disclosed'in over by the gases from the carboniza-tion PaalU. S. Patent 1,210,681.

6-01 the distillation-of various substances Inthe process, according tothe present 55 such as coal, lignite schist, peat, wood and invention, Ieffect the scrubbing of the gas the like;-or by the gases from thehydrogen mixtures containing the volatile solvents to I izing ofdifferent solid or liquid products'; be recovered; by means of theliquids which by the gases obtained from the cracking of are formed bythe hydrogenized terpenes heavy oils; by the natural gas from oil eitherpure or mixed with other suitable fields and in a general manner by allthe products or reagents. As an example of the natural or artificial gasmixtures found in terpenes, I may mention ordinary turpentine industrieswhich produce or utilize volatile which is the most largely used memberof this solvents; group. The said hydrogenized terpenes are Experiencehas shown that the hydrogencaused to act upon the gas mixtures contaln-65 ized derivatives of naphthalene-or hydndes ing the volatilesubstance-s to be recovered, in of na hthalene known as tetraline andsuitable conditions for instance by scrubbing,

decalme-may be used alone or mixed bubbling, surface contact and thelike, and with other scrubbing liquids (for instance they will absorbthe said substances. The

with bodies having phenolic functions such volatile products are-thenseparated by a 70 as the phenols or cresols or products consuitabledistillation of the scrubbing liquids,

taining the same) for the recovery of volatile and are condensed in theknown manner,

solvents according to my French Patent No. while at the same time Iobtain the scrub-- 554=,3 27 of the 21st ofJuly, 1922, and the bingliquids in their original state; the lat- 25 addition thereto 'No. 27,694 of the 14th of ter are again supplied to the circulation, the 75May, 1923; and it has also been found that affording the recovery ofsaid volatile prodthe hydrogenized hydroaromatic. or ucts by means ofknown apparatus, on the alicyclic derivatives also constitute in thecontinuous working principle. same conditions excellent scrubbingliquids These substances have high absorbing which have a very greataflinity, 'or absorbpower and have a pleasant odor which 15 30 ingpower, for-the'various volatile solvents. capable of largely covering upthe disagree It has thus been found that the terpenes able odor of manyof the substances hereto- (hydrocarbons of the formula C H and fore usedin the art. their derivatives will, by asuitable hydro- I claim--genizing, be transformed into liquids having 1. A process for therecovery of volatile 5 a specially marked efiicacit'y for the recovery,normally non-gaseous substances carried in by the scrubbing process, ofgas mixtures'on gaseous mixtures, which? comprlses the use thecontraflow principle. Pinene, which is as absorbing agents, ofhydrogemzed terthe simplest body of the series, and is the penes. z I

40 essential constituent of turpentine, will fur- 2. A process ofabsorbing vapors of norto nish, when it is hydrogenized, a liquid whichmally'non-solid volatile substances from gas is as clear and limpid aswater and possesses mixtures carrying the same, by treating such a mostremarkable absorbing power; it i gas mixtures with an absorbent liquidconsoluble in all proportions in the known taining a hydrogenizedterpene together scrubbing liquids such as the tar oils, the withaliquid which is itself capable of use Vaseline oils, the cresols andother scrubbing as an absorbent for the said volatile subliquids'of thesame class, and will even act tances, and which liquid has a boilingpoint as a common solvent for some of these liqsufficiently higher thanthat of the solvent uids as are notmisci le with each other. to becollected therein to allow the latter to 60 The substances hydrogenizedterpenes as be subsequently largely separategd therefrom I by fractionaldistillation, and which liquid solvents, and capable of subsequentlybeingis' also miscible with the hydrogenized t rlargely freed from; thelatter, for producing in pene, without destroying the latter. a mixedabsorbent liquid, and thereafter A process of recovering th v o fbringing the solvent vapors into contact -normally, liquid volatileorganic solvents with Said mixed absorbent material whichcomprises thesteps of adding a hy l t ny r f I afiiximy ig drogenized' terp'ene'toaliquicl which is itself capable-of absorbing v'apors'of organic 'JEANBREGEAT.

